Broke A Router Bit Yesterday

[crokett]

I was being dumb. Routing the grooves for some tounge n groove door frames. Rather than set up the dado stack I went with a 1/4" router bit - quicker setup. Tried to take too deep a cut and snapped it off. Had to use the dado stack anyway and I lost a bit.

[Uncle Cracker]

A 1/4" bit? No great loss... I won't use 'em except in a trim router. Good thing it didn't nick you up (or worse) when it went. It does make you stop and think about those safety glasses before you switch 'er on...

[Knottscott]

BTDT with exactly the same style of bit doing pretty much the same thing you did. The education factor was worth the price of the bit! ...

[poolhound]

Ditto - BTDT as well.

When I Started out I got one of the 1/4" sets. It didnt take long to realize that 1/2" is the only way to go except as you say with trim routers. I think I broke 3 of the smaller straight bits they are so fragile by comparison, try to take too much with one pass or plunge too deep too quick and thats the end of that bit.....

Jon

[BigguyZ]

Is is just a matter of taking too large a cut too fast? Otherwise, I don't quite see that the issue would be with using a router bit to groove those boards...

[Popeye]

I do alot of doors the same way. Stub tennons make a nice solid door. But..... even though I haven't broken a bit, my next bit purchase is gonna be a 1/4" slotting cutter to make doors with. Faster and safer I think. Pat

[LarryG]

The only bit I've ever broken was a 1/4" straight bit. I didn't think I was taking too big a bite -- I generally don't exceed the 1/4" x 1/4" rule -- but perhaps I was. The bit had a 1/2" shank, but that didn't really help since the metal has to neck down to 1/4" anyway.

It's probably a wonder we don't all break bits this small more often. If you examine a 1/4" bit closely, you'll realize that there's just not a whole lot of metal there in the middle.

[eccentrictinkerer]

Yesterday musta been a bad mojo day for router bits.

I was repairing a customers cracked medicine cabinet door yesterday by routing a slot to fill with new wood. I hit a small pin nail and knocked an 1/8" of carbide off the bit.

I had just picked the bit up at Rockler's 30 minutes earlier!

[LCHIEN]

You did not say whether it was a solid carbide spiral up- or down-cut bit or whether it was just a steel bit with carbide tips.

I broke a solid carbide 1/4" straight bit cutting too deep. Trying to do a 1/2" thick plywood cutout in one pass. After inquiry at MLCS their customer service guy told me to take like 1/8" deep pass at a time and sent me a new bit.

I think basically if you look at the cross-section area of those 1/4" bits there's not a lot of metal there, mostly air. so they are real easy to break. Buy a few extras, they're almost expendable and in the case of the spiral bits, hard to sharpen and brittle (as the bit dulls, you'll push harder and eventually end up breaking it), plan on them not lasting forever. I bought a handful last time Holbren has a sale deal on spiral bits.

[JimD]

I have had relatively bad luck with cheaper bits (my favorite is MLCS) that neck down. I've broken a 1/2 shank 1/4 inch bit without cutting real deep and an inexpensive 1/2 inch diameter 1/4 inch shank dovetail bit. The CMT replacement is still going strong (after a dozen or so drawers made of 1/2 BB dovetailed on all four corners). I think the heat treatment may be a bit off or something reducing toughness. I have not managed to break my 1/4 spiral bit even though it's getting a bit dull and I force it a bit sometimes.

I rarely use a router to make a dado. I will if it's small but if I have a bunch of cutting to do, I use the dado set and I have used a slotting cutter. Sometimes I just make multiple passes with the regular blade on the BT3100 (the micro-adjust is handy for getting the width right).

Jim

[Bruce Cohen]

David,

Welcome to the club. I always try to get 1/2" shank bits (if the cutter comes that way). They're stronger and last longer, although you still can break them if you take too deep a cut or rush the cut DAMHIK.

Bruce